Well here we are again: Mid flower problems

[Sangmang]

Almost at week 4 of flower. Fan leaves are showing tip and edge burning/browning. Some have small dead spots. I had the same exact issue last grow but was using tap water and have switched to RO this grow. Im in coco and haven't exceeded 700ppm feeding. I'm feeding every 3 hours for 1 minute and get some runoff each time. Now for the first time my runoff ppm has increased(900) and my runoff ph has dropped to 5.0. I have a feeling that Nitrogen excess has something to do with this issue.

Typical feed
R/O water, coco, 1.5gal pots
150ppm epsom
100ppm CaliMagic(includes 1%N)
450ppm MGB(emerald harvest 3 part)
700ppm total
After mixing the res its at around 5.0ph and 12ml of ph up is needed in my 15gal DTW drip reservoir to reach 5.8-6

I'm on the Mid Flower ratio which is 2-5-10(G-M-B) and diluting to above strength.

I flushed today with calmag solution(300ppm) until the runoff was the same as input(300). I also further diluted my total res strength to 450ppm by adding more r/o water to the mixed res described above just to be safe.

My environment also may be the culprit. The RH has increased during this rainy week to about 60-65%. Temp is usually 75f. Could it be that transpiration is slow as a result and the plants are being burned? My fans run 24/7(440cfm vent and 3 small clip fans). 300w mars hydro tsl2000 20" above canopy.

On a side note, I have quite a lot of springtails(confirmed) in my medium. I will probably try to eliminate them to be safe although its generally accepted that they're harmless.

Very old fan leaf

 

[Sueet]

Don't eliminate them (springtails), they wont hurt your plant. They are a good clean-up crew, and their poop is good plant food. Idk anything about coco so I can't help with that, but your plants look really good to me. It might be a bit of excess potassium burning the leaves.

 

[Sangmang]

Don't eliminate them (springtails), they wont hurt your plant. They are a good clean-up crew, and their poop is good plant food. Idk anything about coco so I can't help with that, but your plants look really good to me. It might be a bit of excess potassium burning the leaves.

Thanks I appreciate that. I was just alarmed at how many there were. I'll leave them be then. And yeah they look pretty good now but last grow it progressed to looking not great so I'm just trying to figure this out once and for all.

 

[Sangmang]

I'm not confident that it'll work but I put a few lbs of damprid around the tent in a few containers to see if it lowers my humidity a bit. I put a dehumidifier in the basement recently but it's not incredibly effective so I might need a bigger one.

 

[Jypsydog]

Spots are CA, feed seems low. Mid flower in coco I'm in the 900's.
If you want to really know MORE about coco, check this guy out. GREAT BASICS!

Cannabis Grow Guide - Coco For Cannabis - Science and Practice

Cannabis grow guide: articles, tutorials, DIY projects & more! Dedicated to the science and practice of growing cannabis in coco perlite and other media.

www.cocoforcannabis.com

 

[Sangmang]

Spots are CA, feed seems low. Mid flower in coco I'm in the 900's.
If you want to really know MORE about coco, check this guy out. GREAT BASICS!

Cannabis Grow Guide - Coco For Cannabis - Science and Practice

Cannabis grow guide: articles, tutorials, DIY projects & more! Dedicated to the science and practice of growing cannabis in coco perlite and other media.

www.cocoforcannabis.com

When I try bumping up to around 900 I feel like I get nute burn and N tox and stuff. Are you multi feeding?

 

[bluter]

i read that leaf edging as a potassium ask.
have had the same thing and halted it with a bump in nutes. it shows up a fair bit as i use mega crop.

a little bloom booster right now would not be a bad idea. you get the pk without the n interfering.

 

[Sangmang]

i read that leaf edging as a potassium ask.
have had the same thing and halted it with a bump in nutes. it shows up a fair bit as i use mega crop.

a little bloom booster right now would not be a bad idea. you get the pk without the n interfering.

I appreciate the feedback. Maybe I'll try hand feeding for a day with a decent bump in nutes.

Tbh I'm not sold on/don't understand the idea of Bloom boosters. I'm under the impression that the base nutrient's ratios which are adjusted throughout the grow provide enough PK. BUT ive never tried it so I'm sure I will in the future. I'm just gonna stick to base nutes with these strains until I'm dialed in before I add more bottles to the mix.

Having said that, could I just increase the amount of Bloom(0-5-4) I give as a PK boost?

 

[bluter]

yes. that'll do it.. it doesn't need to be piles.
as mentioned already i'd be looking closer to 900 ppm.

just keep an eye on stuff. you're running in to the issue now as it's solidly in flower and looking for a little more.

i also read this as a pk ask with phos showing a little more than the other plants.
you do look a touch high in N on this one, but it doesn't stand out so much as an issue to me.

it's all kinda normal asks from a plant when they start aggressively building buds.

 

[Sangmang]

@bluter I actually was considering a switch to megacrop. Are you enjoying it?

 

[Sangmang]

So hand fed them several times today with a 900ppm solution at a ratio that includes more P&K. Its too early to see any difference however my runoff ppm suddenly went off the charts. Like higher than my meter can read(over 1800). Literally yesterday I flushed the runoff down to 300ppm with calmag solution. What could cause the runoff to spike so bad like this?

I really have a feeling that my VPD being off and the traspiration being slow is causing them to not be able to uptake nutrients and some things are getting locked out. My vpd is around .85 and should be more like 1.3 or something from what I've gathered.

 

[Jypsydog]

When I try bumping up to around 900 I feel like I get nute burn and N tox and stuff. Are you multi feeding?

I grow hempy buckets, I feed when needed.(once a day when they get blasting!) I also run my cal/mag@ 250ppm and my pH in flower @ 6.2.
Stopped checking runoff and worried about my VPD instead. Your VPD corrected helps clear up nute burn issues.
Been running Maxibloom lucas for the last 8 years and nothing on my shelf has a cartoon on the bottle.
I use drops to check pH, the variance in pH is good for the plants. Just has to be close.

 

[bluter]

i run hempy buckets with mega crop. it's a simple system but there's always gonna be a few things in flower going on.

So hand fed them several times today with a 900ppm solution at a ratio that includes more P&K. Its too early to see any difference however my runoff ppm suddenly went off the charts. Like higher than my meter can read(over 1800). Literally yesterday I flushed the runoff down to 300ppm with calmag solution. What could cause the runoff to spike so bad like this?

I really have a feeling that my VPD being off and the traspiration being slow is causing them to not be able to uptake nutrients and some things are getting locked out. My vpd is around .85 and should be more like 1.3 or something from what I've gathered.

you only need to feed as often as you normally would. don't chase run off, it has no useful info for you.

i ignore run off and work with the vpd i'm given.. i don't run humidifiers , dehumidifiers, ac etc. my conditions shift seasonally, it would be too costly to buy all the environmental control. if you can create good vpd conditions i would definitely do it.

 

[Jypsydog]

i run hempy buckets with mega crop. it's a simple system but there's always gonna be a few things in flower going on.



you only need to feed as often as you normally would. don't chase run off, it has no useful info for you.

i ignore run off and work with the vpd i'm given.. i don't run humidifiers , dehumidifiers, ac etc. my conditions shift seasonally, it would be too costly to buy all the environmental control. if you can create good vpd conditions i would definitely do it.

Hempy for the win...

 

[Sangmang]

So I can't get my vpd right when its rainy and humid like this. Even with a 50pint dehumidifier in the basemeny filling up every day my tent stays above 60%

Just want to update the pics as the problems has slowly progressed so maybe it'll be easier for someone to diagnose.

 

[bluter]

the edging is a pk ask. quite a common ask, and sometimes shows no matter in some strains.
a bump in feed is the usual fix. a mild bloom booster here could hit it as well.. you don't want it going too much deeper.

60% rh is high, but not bad, or unworkable. i'd be on the watch for mold.
you're doing great. enjoy the finish.

edit : had a look back. you're a bit later in flower. you can probably just ride them til finish from this point. i probably would leave them depending how hot the current mix was.

 

[Sangmang]

the edging is a pk ask. quite a common ask, and sometimes shows no matter in some strains.
a bump in feed is the usual fix. a mild bloom booster here could hit it as well.. you don't want it going too much deeper.

60% rh is high, but not bad, or unworkable. i'd be on the watch for mold.
you're doing great. enjoy the finish.

edit : had a look back. you're a bit later in flower. you can probably just ride them til finish from this point. i probably would leave them depending how hot the current mix was.

Ive been feeding like 5x a day and I'm wondering if I should dial that back. I'm in 100% coco.

 

[bluter]

5x a day is a wow.

are they dry in between ?
i'd feed to 10% run off once to twice a day in coco in flower, at about 1/2 bottle chart feed strength. as a rough guess.

 

[Sangmang]

5x a day is a wow.

are they dry in between ?
i'd feed to 10% run off once to twice a day in coco in flower, at about 1/2 bottle chart feed strength. as a rough guess.

No I don't even let them lose much saturation at all. I get at least 10% runoff 5x a day. I was just afraid of salt buildup like I had last grow. Yeah ive been mixing a little above 1/2 bottle strength. I'm going to try to reduce the 250ppm of CaliMagic I've been adding because it adds N and I don't like throwing the NPK ratio off like that. I'll just try increasing my 3part nutrient strength and probably try a pk boost for a res and see what happens. I appreciate your help.

 

[copperrein]

the edging is a pk ask. quite a common ask, and sometimes shows no matter in some strains.
a bump in feed is the usual fix. a mild bloom booster here could hit it as well.. you don't want it going too much deeper.

60% rh is high, but not bad, or unworkable. i'd be on the watch for mold.
you're doing great. enjoy the finish.

edit : had a look back. you're a bit later in flower. you can probably just ride them til finish from this point. i probably would leave them depending how hot the current mix was.

When you say 'ask', you mean the plant is asking for more?